Start in an Enclosed Area Rather than clipping on the dog's leash and heading out the door, give the dog time to get used to his leash. Start off indoors or in a fenced in yard. Clip the leash on the dog's collar and let him go. Allow him to drag the leash around behind him and get used to having it attached to his collar.
Don't Let Him Chew Many dogs view the leash as just another toy. Don't let your dog get into the habit of chewing on the leash. Keep some of his favorite toys on hand to distract him. Try throwing a ball for a game of fetch. This will get him used to the feel of the leash, but keep him from treating it like one of his toys. If you just can't seem to distract him from chewing on the leash, you may want to try putting Bitter Apple on it.
Pick Up the Leash Once the dog is comfortable having the leash attached to his collar, it's time for you to pick up the leash. Stay in the enclosed area, and simply hold the leash. You can call your dog to you, and give him some treats while you hold the leash. This isn't a lesson in walking on the leash, simply a way to get the dog used to having you hold the other end of the leash. If the dog or puppy is pulling or struggling on the end of the leash, try to distract him or follow him.
Work on Loose Leash Walking As soon as your dog is comfortable with having you hold the other end of his leash, you're ready to teach him to walk on a loose leash. It's important that you start this as soon as your dog's comfort level allows, so he doesn't get into the habit of pulling on the end of his leash.
Give the WALK Command Start out on your walk with the dog at your side, give the command, WALK and begin walking. You can even use a treat held in your hand down by your side at his head level to get him walking alongside you on the leash, and then occasionally make him stop and sit for the treat.
Stop and Go When your dog pulls at the end of the leash, stop immediately and do not budge. Never allow your dog to move forward when he is pulling or lunging. This way, you are teaching him that the only way for him to get to where he wants to go is by leaving some slack in the leash.
As soon as there is some slack in the leash, you can begin again. Give your dog the command "WALK" and start moving forward.
Some dogs can sit and decide not to move. In this instance, walk a few steps away, go down on one knee and encourage him to come to you using a treat. Then set off walking again.